The Me262 was the first operational jet fighter, again with Ohain's engine.
I think "Ohain's engine concept" would be more correct.
Ohain worked at Heinkel and developed the HeS 011 engine. However, the Me 262 was equipped with the Junkers Jumo 004, which was based on Ohain's design, but developed without him. The first test flights were actually done in 1942 with two BMW Typ P 3302 turbines (later called BMW 003).
https://cs.stanford.edu/people/eroberts/courses/ww2/projects...
I enjoyed flying on the Viscount. It offered a much nicer passenger experience than the current crop of sardine cans.
Decades later I got in a lot of time flying the simulator that Air Canada donated to a tech school.
http://www.vickersviscount.net/Pages_Technical/Rolls-RoyceDa...